1. Field of Invention
The present invention relates to a quick hitch for coupling and decoupling a tool at a rotator for rotating the tool that has a rotator attachment part that is attachable to an excavator arm and/or to a crane boom and/or to crawler forklifts or the like and that has a rotary rotator part rotatable relative thereto, wherein the quick hitch has a coupling part at the rotator side that is fastenable to the rotatable rotary rotator part and has a coupling part at the tool side, wherein the two coupling parts can be brought into engagement with one another and can be latched to one another by at least one latch element.
2. Background and Related Art
Quick hitches are used with hydraulic excavators, crawler-type vehicles and similar construction machinery and earth-working machinery as well as with mobile cranes or loader cranes as well as with similar material handling units to be able to couple different tools to the boom, arm or tool guiding carrier of the respective machine and to be able to replace them with one another quickly, wherein they can, for example, be digging tools, clearing tools, gripping and/or lifting tools such as digging buckets, clam shell buckets, rock grapples, timber or pipe grapples and similar tools. In this respect, one coupling half, part or portion is typically fastened to the tool and a second coupling half, part or portion is fastened to the excavator or crane or to the corresponding machine such that only the two coupling halves have to be moved together and latched. The two coupling halves are in this respect typically moved into one another or toward one another along a coupling axis or a coupling trajectory and can be latched to one another by one or more latch elements that can be moved in and out transversely to the named coupling axis or coupling trajectory. In this respect, hydraulic or pneumatic latch operating actuators can typically be provided for moving the latch elements in and out and can be configured, for example, in the form of hydraulic cylinders. It is also known in this respect to preload the latch elements into a position, for example into the latching position, by spring elements and to use the latch operating actuator only for one direction of movement of the latch elements, for example for unlatching. Independently of this, the latch operating actuators can be supplied by energy lines such as hydraulic hoses, with the energy supply lines having to follow the movements of the coupling half at the machine side and having to be configured as correspondingly multi-axially movable since, for example, a crane grapple of a mobile crane is multi-axially movable with respect to the boom.
If the quick hitch is used in conjunction with a rotator, it is typically not sufficient to lead the energy supply lines around the tilt and pivot axes with a corresponding bulge since such rotators typically do not have any limiting angle of rotation, but can rather—at least theoretically—carry out as many revolutions in the same direction as required. Such a rotator or rotational drive typically has a rotator attachment part that so-to-say forms the fixed stator part and is attached to the excavator arm or crane boom or the like, with the rotator attachment part naturally not really being stationary, but rather also being multiaxially movable by the excavator arm or crane boom and also relative thereto in space, for example being tiltable about two horizontal spatial axes and being travelable as desired in space by the excavator arm or crane boom. The rotary rotator part can be rotated about a rotator axis of rotation relative to the rotator attachment part, with the rotator axis of rotation frequently being oriented upright, in particular when the tool is guided in a suspended manner below the boom arm, to be able to rotate the tool about an upright spatial axis.
Since the coupling half of the quick-coupler at the machine side is naturally fastened to the rotating rotary rotator part so that the tool can carry out the rotational movements of the rotator, the latch elements by means of which the two quick hitch coupling halves are latched to one another also correspondingly co-rotate. An actuation of the latch elements is not very simple in this regard. Even if, for example, a latch adjustment movement can still be carried out relatively simply by preloading the latch elements, special measures have to be provided for the opposite movement by the latch operating actuator or a manual unlatching has to be carried out that requires the machine operator to climb down from the operator cabin. To avoid this, it has already been proposed to provide a rotary union through the rotator for the energy supply of the latch operating actuator, via which rotary union, for example, hydraulic pressure can be applied to the latch operating actuator arranged at the coupling half at the rotator side. Such a rotary union comprises, in the case of a hydraulic supply circuit, an annular passage or a central pressure passage that is to be sealed using corresponding sealing measures at the interface between the rotary attachment and the rotary rotator part. In the case of an electrical energy supply of the latch operating actuator, such a rotary union can comprise annular sliding contacts with which the interface between the rotator attachment part and the rotary rotator part is bridged. In both cases, such a rotary union through the rotator is complex and/or expensive. In addition, the degree of construction freedom for the configuration of the rotational bearing of the two rotator parts is hereby restricted.
Starting from this, it is the underlying object of the present invention to provide an improved quick hitch of the initially named type which avoids disadvantages of the prior art and further develops the latter in an advantageous manner. A simple, but still reliable latching and unlatching of the two coupling halves should in particular also be made possible by a rotator without requiring complex and/or expensive rotary unions being required through the rotator for the energy supply of the latch operating actuator.